In a bolt for fixing a part between its stud welding portion and a resin clip, the resin clip is forcibly fitted forcibly over the shank. Ideally, the resin clip should require only a small effort to be fitted over the bolt shank, but should require a large load to be removed.
For this purpose, as shown in FIG. 2, a conventional stud bolt has been developed. The conventional stud bolt is provided with screw threads 10 having a triangular cross section. The screw threads 10 have unsymmetrical flanks with an inclination of 45.degree. on one side and inclination of 15.degree. on the other side. Although this conventional stud bolt can sufficiently bear the standard resin clip removing load of 35 Kgf, the load required to fit the resin clip over the shank exceeds 8 Kgf. Thus, this stud bolt has the disadvantage that considerable force is required to fit a resin clip over the shank.